The present invention relates to a combination of dual inner and outer tire carrying rims mounted on a vehicle wheel without using a separating means, such as an annular spacer.
The inner spoke members of a dual wheel have a felly, felloe or load-bearing portion comprising a radially outer portion having a radially inclined surface which may merge into outwardly facing dual axially oriented surfaces, and a radially directed surface oriented transversely between the axially oriented surfaces.
The outer spoke members of a dual wheel have a felly, felloe or load-bearing portion comprising outwardly facing axially inner and axially outer pairs of dual axially oriented surfaces and a radially inwardly directed surface oriented transversely between the axially inner pair of axially oriented surfaces.
A rim according to the invention may be used interchangeably as an inner dual or outer dual, rim. The rim has a base edge portion confined and carried by a plurality of radially inwardly projecting clamp lugs. The clamp lugs decrease the effective diameter of a rim, permitting the mounting of relatively larger diameter rims on relatively smaller diameter wheels.
The improved rim clamp lugs are generally T-shaped, having a radially inwardly directed leg portion and a curved body portion with radially outer surfaces for integral attachment to the rim base edge portion, lateral wing portions for seating on dual axially oriented wheel felloe surfaces and a radially inner face with a radially inclined surface for mating engagement with either a wheel felloe surface or a surface on a clamp element of a fastening assembly.
An initial tightening of the fastening assemblies for an inner dual rim mounting will seat the clamp lug radially inclined surfaces in concentric registry with the radially inclined inner spoke felloe surfaces. Thereafter, the seated rim will be locked on the inner spoke members, in axial and radial alignment and registry, by further tightening of the fastening assemblies against the clamp lug leg portions and the full surface engagement thereof with a radially directed wheel felloe surface.
In the embodiment shown wherein the outer spoke members have a felloe with axially inner and axially outer pairs of dual axially oriented surfaces, an initial tightening of fastening assemblies using a generally T-shaped clamp element will seat the clamp lug lateral wing portions in radial registry with the axially inner pair of dual axially oriented surfaces and the clamp lug radially inclined surfaces in concentric registry with a conforming radially outer clamp element surface. Thereafter, the seated rim will be locked on the outer spoke members, in axial and radial alignment and registry, by further tightening of the fastening assemblies against the clamp lug leg portions and the full surface engagement thereof with a radially directed wheel felloe surface.
According to the invention, the clamp lugs are proportioned or dimensioned such that during final tightening, a fastening assembly will elastically stress or minutely deform each clamp lug and the rim base edge portion relative to the plane of the radially directed wheel felloe surfaces to provide the full axial and radial alignment and registry of rim to wheel.
The prior art relating to tire carrying rims demountably carried on vehicle wheels includes patents to be found in Class 301 beginning with Subclass 10R. Other relevant patents may be found in Class 152, Subclasses 406X et seq.
Other prior art known to the applicants includes an adapter ring which makes possible the use of larger diameter (22") dual tires and rims on a smaller diameter (20") wheel with a conventional (28.degree.) mounting bevel. The adapter ring requires a separating means, such as an annular spacer or band. With the adapter ring in place, the rim and tire can be mounted or removed in the ordinary manner. The referenced adapter ring is more fully disclosed in the prior art publication, "Firestone Steel Products Company, Akron, Ohio, Catalog No. F-49, p. 29", (publication date unknown).
The accurate mounting of tire carrying rims on the felloe, felly or load-bearing portion of a wheel has long been a problem in the art. Vehicle operators and industry regulations seek longer tire life and complete safety in operation, even under the most severe of vehicle operating conditions. The tire manufacturers are endeavoring to provide tires which have optimum performance characteristics, including lateral and radial balance. Consequently, it is being required that this art provide elements, the wheels, the rims, and fastening assemblies therefor, which do not deteriorate, hinder or impair the projected performance characteristics of the tires.
Heretofore, the spoked wheel structure of a tire-rim-wheel assembly has been regarded primarily as a load carrying element attached to an axle of the vehicle and carrying the rim. The periphery of the wheel had felly surfaces to pilot or guide the rim into approximate mounting position. Thereafter, fastening assemblies were torqued down or tightened in such a manner that the tire carrying rim would not come loose from the wheel during use. If done correctly, as by an expert and conscientious mechanic, the prior art rim mounting techniques would not deteriorate, hinder or impair the performance characteristics of the tires. However, environmental or extrinsic factors such as warpage, deformation or damage to the rim and spacer or wear of the fastening assemblies could lead to relative displacement or non-alignment of the assembly components during fastening, creating conditions of what are now commonly referred to as excessive lateral (axial) or radial runout or an imbalance of the tire-rim-wheel assembly during vehicle operation.
The concepts of the invention provide wheel spoke members with proportioned or dimensioned felloe surfaces for mating, seating or full surface engagement with coacting surfaces on the radially inwardly projecting clamp lug leg portions by full tightening of the fastening assemblies. The clamp lugs will also provide a combination of a relatively larger diameter tire carrying rim seated and locked by fastening assemblies on a smaller diameter wheel.
An edge lugged rim and fastening assemblies therefor according to the invention, when used with wheels adapted thereto, reduces weight and cost, positively controls and reduces lateral (axial) and radial runout, resists rim warpage or deformation, restricts or locks out the possibility of rim rotation relative to the wheel and provides better balance for the tire-rim-wheel assembly during vehicle operation.